In the setting of familial melanoma, comprising about 10 percent overall incidence of melanoma, the presence of atypical nevi is associated with a nearly 100 percent risk of developing primary melanoma by age 70. However, atypical nevi also occur outside the familial melanoma setting, and it is estimated that 40-60 percent of sporadic melanomas develop from these melanocytic precursor lesions. In patients with familial melanoma and/or Dysplastic Nevus Syndrome (DNS) and likewise, in patients who have a clinical history of sporadic melanoma and numerous atypical nevi, melanoma in situ and melanoma in the radial growth phase (RGP) often develop in contiguous association with atypical nevocytic lesions. Currently, the only way to prevent atypical nevi from progressing to melanoma is to persistently monitor and resect them at the earliest signs of changes in shape, size, and/or pigmentation. However, monitoring these lesions by eye or with a handheld, incandescent light source, as done in most clinical settings, is neither an effective nor reliable way for detecting melanoma arising in or adjacent to atypical nevi. In light of the rising incidence of melanoma worldwide, the present limitations concerning early detection of melanoma when juxtaposed to the observation that a patient is often cured by a wide and deep excision of the melanoma when in its early stages, clearly require implementation of new diagnostic devices and techniques that can noninvasively and reproducibly capture melanoma in atypical nevi at first presentation, i.e. prior to excision and histological analysis. Focusing upon optical imaging as a means to address this need, we previously conducted a study, which provided first-time evidence that macroscopic Spectral Imaging has the capacity to detect, in vivo, melanoma arising in melanocytic precursor lesions. Based upon this finding, we now would like to take this project one step further and determine, whether a newly designed acousto-optic tunable filter (AOTF)-based mesoscopic Spectral Imaging device can establish a spectral signature of melanoma developing in or in contiguous association with atypical nevi.